Air conditioning method and apparatus



Aug. 14, 1934. E, M NKEL 1,970,301

AIR CONDITIONING METHOD AND APPARATUS Filed Dec. 10, 1931 BY 09x52 M, M 60 1:

ATTORNEYS Patented Aug. 14, 1934 Nl'l'E D STATS AIR CONDITIONHNG METHQD APPARATUS 14 Claims.

My present invention relates primarily to air conditioning apparatus, more particularly for imparting to air the proper temperature and humidity, for human comfort in dwelling houses.

auditoriums, ofiices, stores, factories and the like.

It is an object of the invention to effect air conditioning by automatic operation and control, which shall yet involve simple and inexpensive apparatus of relatively small bulk and unlikely to become deranged, and in use will assure not only correct temperature but also correct humidity without excess or deficiency.

Another object is to eflfect air conditioning with substantial economy in power consumption; with it; economy in service, by wholly dispensing with the need for manual access for any purpose and with economy of materials by avoiding the use of expensive or perishable humidity absorbents.

Another object is to provide an installation of the above type which can be embodied in apparatus so simple and compact that it admits of being substituted for the furnace of a dwelling heated by a hot air system and will serve to maintain the air conditioned at a uniform degree of temperature and humidity summer and'winter.

A feature of the invention is the regeneration' of the humidity removing medium during and preferably throughout air-conditioning operation, so that such medium at'no time becomes spent or inactive. Thus it becomes unnecessary to employ a medium that hasa strong avidity for moisture, but any of a wide variety of inexpensive substancesthat promptly reach a humidity in a state of equilibrium with that of the atmospheric surroundings is suitable. Any of a wide variety 7 of organic tissues is suitable, but cellulose in the form of ordinary cotton fabric is ordinarily preferred because of its low cost.

According to anotherfeature the humidity absorbing medium is regenerated by removal of the excess moisture at a region isolated with respect to the air being conditioned and then returned for re-use in a continuous cycle.

In a preferred specific embodiment, the conditioning chamber has an inlet port for the raw air and a delivery port discharging the conditioned air. A regenerating or drying chamber is disposed adjacent the conditioning chamber. The moisture absorbing'medium in the illustrative embodiment comprises a continuousflexible run in the form of a strand, band, web or belt of cotton fabric wound over rollers respectively in the conditioning and regenerating chamber and a motor continuously drives said run as the air passes therethrough, to advance the successive lengths of the moisture laden run through the drying chamber back into the conditioning chamber, for re-use in a continuous cycle.

According to another feature of the invention, the'incoming air is subjected to a heat inter- 60 change instrumentality in the form of a radiator" automatically controlled in its efiectiveness by a temperature responsive instrument at the discharge port of the installation, preset to maintain any desired temperature. In a complete installation, it is desirable to have in addition to a cooling'medium an air heating medium also subjected to the temperature responsive instrument to heat the incoming air to the proper temperature in cold weather.

Another feature of the invention isthe automatic control of the humidity of the air discharged from the installation, by regulation of the effectiveness of the regenerating or drying instrumentality.

In a preferred embodiment, the humidity absorbing medium is subjected in the regenerating chamber to a water abstracting agency preferably in the form of a heater, the operation of which is controlled from a humidity responsive instru- 80. ment at the discharge port of the installation, I preset to maintain a definite humidity at a definite temperature.

Another feature is the automatic injection of additional moisture to the raw air in those cases in which the humidity would be insufficient at the temperature of conditioning. It is preferred in this relation to provide a humidity responsive instrument at the inlet port and to inter-relate it with a water spray set into operation when the instrument registers a humidity considerably lower than that required for the conditioned air.

While the various featuresenumerated are each meritorious alone or in combination with known apparatus, it is preferred to utilize some or all of these various features in combination.

Thefigure is a showing, purely diagrammatic of a preferred form of air conditioning installation. r

Referring now .to the drawing, there is shown a unit which may comprise a sheet metal casing 10 subdivided by a transverse wall 11, into an air. conditioning chamber 12, preferably extending the major length of the apparatus and a regenm5 crating or drying chamber 13 illustratively at the top of the chamber. The chamber has at one side thereof an inlet port 14 through which is admitted the raw air to be conditioned and it has at the opposite side thereof a discharge port 15 no delivering the conditioned air into the building, auditorium, store, factory or room.

A humidity absorbing medium, illustratively in the form of an endless web, band or belt 16, having moisture absorbing and moisture releasing properties is shown extending in part longitudinally of the conditioning chamber 12, in part in the drying chamber 13. The web is shown mounted upon a pulley or roller 19 near the lower end of the conditioning chamber and a roller 20 in the drying chamber, guide rolls 17 at the dividing wall 11 preventing communication of the air in the two chambers.

A system of bafile plates consisting illustratively of plate 21 extending longitudinally of conditioning chamber 12 and between the two runs of the web 16 and transverse plates 22 and 23 between the webs and the walls of the chamber 12 compels traverse of the raw air injected-preferably by a suitable blower (not shown) several times through the fabric, as shown by arrows, in its traverse from the inlet port 14 to the discharge port 15. An electric motor 24 preferably drives conditioned air.

the roller 20 continuously throughout use, to bring the moisture laden portion of the web into the heating chamber where excess moisture is driven off and to return the drier portion to the conditioning chamber for operative use.

While any of a wide variety of humidity absorbing media may be used for the purpose, as for instance, silica gel, calcium chloride or the like, which absorb humidity "physically, or any of a variety of other media may be used which combine chemically or pseudo-chemically with the water, and while such medium is mounted in any manner to be cyclically water laden and dried, or regenerated for re-use, as for instance on an endless carrier, it is preferred to employ for the purpose inexpensive organic tissue of the type that readily enters into a state of equilibrium in its moisture content with respect to the humidity of the surrounding air. Great avidity for moisture is not required, since the course of the medium through the conditioning chamber by appropriate use of rollers, can be sufficiently great and the advance thereof at such speed as to eifect absorption of humidity at the desired rate, wholly regardless of the specific absorbtive coefiicient of the fabric.

A satisfactory tissue preferred by reason of its low cost, is cellulose, preferably in the form of ordinary woven cotton sheeting of any suitable weight.

The apparatus has an important utility for cooling dwellings, auditoriums, ofiices and the like during summer. For this purpose, a suitable heat exchanger 25 is disposed in the course of inflow of the air, illustratively at the inlet port 14 and supplied from a source of cold water 26, for instance. By means of a valve 27 normally urged closed by spring s, the cooling fluid may be turned on or off. This valve is preferably controlled from a temperature responsive instrument 28 at the discharge port 15 of the installation, where it is subjected to the temperature of the That instrument is set to permit of a maximum predetermined temperature, say of '75 degrees F. The construction of the temperature responsive instrument and its interrelation with the radiator may be in accordance with practice familiar to those skilled in the art. Illustratively, the instrument 28 is a dry bulb ther ture. The metal piece 30 is connected by a conductor 31 to a solenoid 32 acting upon the opcrating arm 33 of the valve 2'7. 'A grounded battery 35 is connected to the thermometer and the solenoid is grounded as at 36. Accordingly, so long as the temperature of the conditioned air is not less than the valve determined by the position of terminal 30, the radiator remains in operation, to cool the air being treated until the thermometer 28 drops sufliciently to break circuit with terminal 30 permitting closure of the valve 27 by it's spring s, and disconnection of the radiator until the temperature again rises.

In a complete system, there is provided in addition to the cooling agency, a heating agency to function in cold weather where the air must be heated rather than cooled to the desired temperature. For this purpose, in addition to the terminal 30, a terminal 3'7. at lower level is'provided to coact with the thermometer contact 29 when the temperature reaches a low level, and is connected by a conductor 38 to solenoid 39 operative to throw the valve 27 (which in this case is a three-way valve), for connection with a source of steam 40. i

In order accurately to control the humidity of the air delivered from the conditioning installation, so that it is neither too wet nor too dryat the temperature, to which it is conditioned, a humidity responsive instrument 41 is preferably provided, subjected to the conditioned air and inter-related with the regenerating or drying chamber to determine the efficiency of operation of the latter. Thus, if the raw air is of only slightly excessive humidity, it is preferred to operate the humidity abstracting medium 16 in such manner as to take but little moisture, and conversely where the raw air is heavily laden with humidity, the abstracting medium should be so operated as to abstract moisture at relatively greater rate.

In the illustrative embodiment shown, the humidity responsive device is a wet bulb thermometer 41 including a wick 42 about the thermometer bulb dipping into the cup 43. A terminal 44 coacts with contact 45 on the wet bulb thermometer and is set, so that circuit is closed, say at 65 degrees F., a temperature say 10 degrees lower than that of the dry bulb thermometer. By means of a conduit 46, terminal 44 is connected to a solenoid 47 operating through linkage 48 on a control valve 49 determining the inflow of ,steam through pipe 50 to the hollow roller.

20, which thus constitutes a drying roll. Chamber 13 has a vent v communicating with the air outside of the chamber or room being conditioned.

By the automatic operation of the installation as thus far described, the air would thus be conditioned illustratively to a temperature of '75 degrees, with a moisture content that would saturate atmosphere at 65 degrees.

To render the apparatus of relatively universal utility in all climates, it is desirable to provide means which will automatically add humidity to the air rather than abstract it therefrom under those conditions of operation or in those desert regions in which the atmosphere is too dry. For this purpose, a water spray apparatus 50' may be provided in the course of inflow of air, say at the intake port 14, controlled from a valve 51, under control of a humidity responsive instrument illustratively a wet bulb thermometer 52, having an adjustable electric terminal 53, preferably set at a temperature lower than that of the wet bulb thermometer 41. A conduit 54 contions to take out the excess and brings the humidity to the proper value, by operation above set forth.

Apparatus on the principle set forth may be constructed of any desired capacity to suit the requirements of alarge auditorium or of a small dwelling. It is sufficient to knowthe specific absorption coefficient of the cellulose or other absorbent used and to provide a sumcient length and speed of advance to accomplish the desired result. The device has a particularly useful application in a small embodiment when substituted for the furnace of a dwelling of the type heated by a hot air system in which case it maintains any predetermined temperature and humidity throughout the building, at all seasons.

Normally the drying or regenerating chamber will not completely dry the cellulose fabric 16. Assuming the humidity of the air being treated to be such that the web of cellulose contains say four percent of moisture as it is about to enter the heating chamber, the operation of the latter may be such that the web length having the regenerating chamber and, entering the conditioning chamber 11 has a moisture content, say of 2.5 percent. This, under some conditions of operation, would afford a gradient relative to the humidity of the air such that by the time the web has traversed the conditioning chamber and is about to reenter the drying or regenerating chamber, it will then have reached equilibrium as to moisture content relative to the humidity of the air by again containing say four percent of moisture.

According to the present invention, the effectiveness of the drying or regenerating chamber is maintained atalltimes at value properly coordinated with respect to the differential humidity of the raw air and the air in conditioning state. The humidity will neither become too high nor too low for the intended purpose.

It is of course, understood that any appropriate blower or suction fan, ventilator or ventilator system of type well known to those skilled in the art, could be used to cause raw air to be continuously passed through the conditioning apparatus and stale air to be withdrawn from the room, building or chamber.

While there has been disclosed a substantially complete system which will bring the air to both the correct temperature and humidity for an ideal state of comfort for the human body under ordinary indoor conditions, it will be understood that the system could readily be set to produce any desired condition of temperature or humidity suited for instance, to particular conditions of therapeutic treatment. It will also be understood that the system could be applied to advantage in manufacturing establishments, where a particular degree of temperature and humidity is to be attained for best results, as in the dehydration of air for blast furnace or combustion apparatus, in drying equipment, in printing plants, and in textile mills among other applications.

The term regeneration is generically used to define restoration of the saturated humidity absorbing medium to operative condition. The

term is intended to embrace not only the mere drying or driving off of moisture, as illustratively disclosed in the drawingsof the present application, but is generic to other methodsor instrumentalities for withdrawal of excess water either by mechanical, thermal or chemical means.

It willthus be seen that there are herein described apparatus and methods in which the several features of this invention are embodied, and which in operation attain the various objects of the. invention and are well suited to meet the requirements of practical use.

As many changes could be made in the above construction, installation and method, and many apparently widely diiferent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in. the drawing, or described in the.

specification, shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention,- what I claim as new and desire to secure by Letters Patent is:

1. Air conditioning apparatus including a humidity absorbing medium, an air intake port arranged to direct the 'air across said'medium, an air delivery port discharging the conditioned air into the room, a temperature metering device at' said dischargeport, a heat interchange device at said inlet port, and interlock means between said temperature metering device and said heat interchange device to heat or cool the admitted air to a pre-determined temperature.

2. Air conditioning apparatus comprising a conditioning chamber having a humidity absorbing medium, an air inlet port having heating means and cooling means thereat, an air delivery port discharging the conditioned air for use, said delivery port having temperature responsive means thereat, said'latter means interrelated with the heating and the cooling means to cause the air to be heated or cooled to a desired temperature.

3. Air conditioning apparatus comprising a humidity absorbing medium, regenerating means for abstracting excess moisture from said medium and discharging it exteriorly of the chamber to be conditioned, humidity responsive means subjected to the conditioned atmosphere and interrelated with said regenerating means to predetermine the effectiveness of regeneration in accordance with the relative humidity of the raw and the conditioned air.

4. Air conditioning apparatus including a humidity absorbing medium, means for removing moisture laden medium from operative position and subsequently returning it for reuse, means for regenerating such moisture laden medium while out of use, and humidity responsive means a predetermined range of temperatures, a humidity conditioning chamber having a humidity absorbing medium, a regenerating chamber for said medium having a moisture abstracting instrumentality therein, means for continuously passing moisture laden medium from said conditioning to said regenerating chamber and regenerated medium from thelatter to the former chamber, humidity responsive means subjected to the conditioned atmosphere, and interrelated with said regenerating instrumentality' to determine the efliciency of the latter thereby to bring the humidity to the desired value at the desired temperature.

7. Air conditioning apparatus comprising a conditioning chamber and a drying chamber, a continuous band of humidity absorbing medium extending through both of said chambers, means continuously feeding said band to advance the moisture laden part thereof to the drying cham-' ber, and the dried part thereof to the conditioning chamber, an inlet port admitting air to the conditioning chamber, heat interchange means at said inlet port to bring the admitted air to the desired temperature, a humidity responsive member in the path of discharge of conditioned air, said latter element being interrelated with the drying medium to control the effectiveness thereof, thereby to bring the discharged air to the desired degree of humidity.

8. Air conditioning apparatus comprising a unit including a conditioning chamber having an air inlet port and an air discharge port, a drying chamber, roller means in said chambers, a continuous web of moisture absorbing tissue extending about said roller means, and through said two chambers, a drying apparatus in said drying chamber, and humidity responsive means at the outlet port of said unit, and associated with said drying apparatus to control the effectiveness thereof in accordance with the quantity of moiscontact with spaced parts of the web and chamber walls to direct the air in a multiplicity of traverses through the fabric in its course from the inlet to the outlet port.

10. Air conditioning apparatus including means for humidifying excessively dry air, said apparatus including humidity responsive means sub- Jected to the raw air, a source of moisture under control of said humidity responsive means to moisten the air beyond requirements, and a moisture abstracting medium in the path of air flow from said humidifying means, to bring the humidity of the air down to the required value.

11. The method of automatic air conditioning which consists in passing the air through a humidity absorbing medium, continuously regenerating said medium, governing the effectiveness of such regeneration in accordance with the humidity of the air delivered therefrom, and governing the temperature of the air .to be treated in accordance with the departure of the temperature of the output from a predetermined value.

12. An air conditioning installation comprising a conditioning chamber, a drying chamber, a continuous web of humidity absorbing tissue extending through both of said chambers, an air inlet port to said conditioning chamber, an air out port from said conditioning chamber, air cooling means at said inlet port, a dry bulbthermometer at said discharge port interrelated to control the effectiveness of said cooling means to maintain a predetermined temperature, a wet bulb thermometer at said discharge port interrelated with said drying chamber to control the effectiveness of drying in accordance with a predetermined read.- ing tobe. maintained with said wet bulb thermometer, and meansfor continually moving said humidity absorbing tissue.

13. Air conditioning apparatus including a humidity absorbing belt, a chamber therefor, having .an air inlet and an air outlet and baflle means for directing the air in a plurality of traverses through said belt in the course of the air flow from the inlet to the outlet.

14. Air conditioning apparatus comprising a humidity control chamber having an air inlet and an air outlet, a humidity controlling continuous belt in said chamber, a belt drying chamber distinct from said humidity control chamber and housing part of the length of said belt, baflie means in said humidity control chamber directing the air in a plurality of traverses in its course from the inlet'to the outlet of the chamber, and means for driving said belt in direction opposed to that of the air flow.

EDWARD M. mm 

